Thermostatic fire alarm



March 23 1926. 1,577,892

J. E. BUCHANAN TFKERMOSTATIC FIRE ALARM Fi led Oct. 26, 1925 2 Sheets-Sheet 2 I I 78 57 35 M @Mm ATTORNEY JAMES E. BUCHANAN, or rAwrUcKEr, :anonn ISLAND.

TI-IERMOSTATIC FIRE ALARM.

Application filed October 26, 1925. Serial No. 64,764.

To (ZZZ whom it may concern:

Be it known that 1, JAMES E. liUCI-IANAN, a citizen of the United States, residing at Pawtucket, in the county of Providence and State of Rhode Island. have invented cer tain new and useful Improvements in Thermostatic Fire Alarms, of which the following is a specification. 7

My invention relates to themostatic fire alarms and has for its essential objects sensitiveness, certainty of action, and simplicity. a

To the above ends primarily my invention consists in such parts and in such combinations of parts as fall within the scope of the appended claim.

In the drawings herewith, which form part of this specification- Figure 1 is a front elevation of my novel device, showing a part broken away, and the gong omitted,

Figures 2 and 3, sections of the complete device on lines 22 and 33 respectively of Figure 1, a

Figure 4, an elevation taken from line 44 of Figure 1, and

Figure 5, a section on line 55 of Figure 2.

Like reference characters indicate like parts throughout the views.

My device comprises an oblong upright back 6 with vertical lateral guide shoulders 7 forming a central guideway 8 extending throughout its length. The back is adapted. to be attached or suspended to a wall, in this instance by a fiat metallic loop 9 attached by a pin 10 to the upper portion of the back. A hook 12 is disposed centrally of the guideway in the front face of the upper part of the back. Below this is a fuse 13 of a metal fusible at a temperature predetermined for the operation of the alarm. Embedded in the upper end of the fuse is a portion of a wire 15 provided with an exposed coiled loop 16 engageable with the hook 12. Embedded in the lower end of the fuse is a second wire 18 with an exposed coiled loop 19 engageable with a hook 20 upon a wire loop 22 passing through a transverse hole 23 in the upper central portion of a fiat rectangular weight 25 slidably mounted in the guideway 8 in contact with the shoulders, and

provided with a beveled lower extremity 26. In this instance a guard strip 28 is fixed by attaching screws 29 to the shoulders.

Below the weight is a circular base plate 31 fixed to the shoulders by screws 32 and provided with-adownwardly directed flange portion 33 resting against the shoulders, the whole forming a cup or housing. A gong 35 has an internally threaded centrally disposed projection 36 adapted to engage the threaded outer end of a post or shaft 38 rotatable in a perforation 39 in the base 31 and in a similar perforation 40 in a front plate 41 supported by posts 42 upon the base. .The lower end of the post has attached thereto one end of a mainspring 44 whose other end is fixed to a rearwardly directed stud or post 46 fixed in the lower portion of the base 31. Fixed inthe, upper portion the latter is a tubular post or stud 47. Engaging the studs-in grooves 48 and 49 respectively is a rear guard plate 50 for the spring and against which the end of the post 38 abuts. Rigid on the post 38 is a ratchet 52 engaged by a pawl 53 pivoted by a pin 54 to a toothed wheel 55 loose on the post. A spring 56 fast to wheel 55 presses the pawl. The member 38 operates as a key shaft when the gong is manually rotated in one direction to tighten the spring, the pawl acting as a check during the winding.

A hammer 58 enclosed by the gong has an arbor stem 60 of flat material provided with a reversely bent end portion 61 pivoted upon a pin 62 fixed in the base and front plates. There are spaced prongs or lips 64 upon the arm portion 61 as shown in Figure 1. The hammer is vibrated against the gong from the shaft 38 through a gear train which includes toothed disk 55 meshing with a pinion or lantern wheel 66 fast to a spur wheel 67 upon a post 68 in the plates. The latter wheel meshes with a second gear 70 fast to atoothed wheel 71 rotatable on a post 7 2 in the plates and engageable with the lips 64 whereby the hammer stem is vibrated.

The gear train is normally locked or re tained against operation by a check device vhich includes a resilient arm or plate 74 fastened to the upper face of the base plate 31 by the riveted head 75 of the pin 46 which extends through a hole 76 in the lower end of the arm. An upturned lug 77 upon the latter has a lateral lip or projection 78 engaging the teeth of the spur wheel and holds the gear train motionless against the force of the spring 44. A pin or plunger 79 slidable in the tubular post 47 projects rearwardly from the post. and: is provided, with a conical or rouudediheaid 8'0 normally pressed by the arm 7 4 into contact with the center of the back 6 at acentral point in the guideway'fiinthe path: of the beveled portion 26 of the weight 25. As the outer end of the pin 79 bears against the rear face of the free end of the arm 7.4, an.

outward movement of the pin throws the 11p. '18 out. of engagement with the spur 7 wheel 67 and releasestlielatt'en. (hen out.-

ward'j pressure upon. the pin. is discontinued the; arm 7'45 mores rearwardly and? again. en:- gages. the teeth oii't he Wlieeli 7 When the temperature adjacent. the memher 1 3; reaches or approaches the fusing )oii1.t the weight -withdraws the, wire 18 i therefrom. so that the, broad point of its beveled. portion descends between. the back 6 and. the head 80 thus impelli'ng the member 79' forwardly to release the train and;v operatethe gongas described. Until the weight I 25' ismanually lifted from contact with. the

head 80" the gong; sounds.

In, a thermostatic fire alarm, a back p110- videdl with a vertical guid'eway,. a hook in spaced, from; the rear oi the gnid'eway, a a

shaft in the. plate a. gong on the shaft, a vibratory hammer carriedv by the. plate and adapted; to contact with the gong, a gear traiin operable to actuate the hammer, a resilient plate fastened near. one. endito the base plate, a projection on the resilient plate normally en gaging. the gear train, at pinhslid ably supported: in the base plate, at right angles to tllCzbiLCk. projecting into. the; path of the weight and' in contact with the. resilient plate whereby the latter will becimoved to release. the train when the weight descends.

In testimony whereof I have affixed my signature.

' JAMES nnormnan. 

